I have a very minor coolant leak somewhere around the radiator area, but I cannot find it! If it sits all night there will be a small puddle under the very front of the car. I've looked all over and can't see any weeping or residue. Any ideas??? Thanks!

 

When my 06 MCS leaked overnight it was leaking at the thermostat housing/gasket.

 

Thanks, I'll check that out.

 

What did u find? My 04 MCS is doing the same thing.

 

My MCS was leaking way up front too and it turned out to be the radiator. Eventually, I noticed a discoloration right in the middle where the coolant was evaporating and leaving a whitish residue. I ended up having to replace the radiator.

 

I just dealt with a fairly major coolant leak in my 05 R53. Turned out it was the water pump. Had nasty coolant all over the front of the block and down onto the oil pan.

 

Mine was a pinhole in the radiator! Just need a system pressure test..

 

Thermostat housing is an extremely common failure on the first gen, odds are good that's your problem. It happened to me, same symptoms. It was fixed under warranty in my case but I don't think it's a pricey issue, even at the dealer.

 

I say either water pump or radiator.

 

Had same issue a while back but couldnt seem to find the source. It turned out to be the radiator. Try taking the plastic splash shield off from underneath the car directly behind the bumper. When I took mine off it was covered in white residue. The dealer told me most coolant leaks go undetected because this oem splash shield catches most of the leak and residue when the radiator fails. Also check the insulating foam on the bottom passenger side of the radiator. When the radiators fail they tend to become hard and have discoloration. Good luck!!

 

FYI.... Just saw that minicarparts.net has K-seal on sale for $12. If it's the radiator, might be worth a try for $12 bucks!!!